Document 6189E53YpaGG8v98zDNL9Xv1
BRAKE SYSTEM SERVICE
LESSON ONE-MODULE 2
Item
Description
1 Measuring a Brake Drum
Item Description 2 Maximum Drum Diameter
Any used brake dram will show some wear. New brake drums are made thick enough to allow for a certain amount of wear and machining. But there is a limit to how much metal can be worn or machined off a drum. Most brake drums are allowed to be oversize 1.5 mm (.060 in). However, this limit may vary. The oversize limit is stamped on the face of the brake drum or published in the vehicle Workshop Manual.
To determine the drum size use a Rotunda Brake Drum Micrometer 164-R2728 or equivalent. The drum size must never exceed the specified limit.
Brake System Diagnosis and Repair
September, 2005
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